What size is your inverter, and is it big enough?

[KompetentKrew]

Obviously the most correct answer to the question "what inverter should I buy?" would be achieved by measuring device consumption, but when I live aboard soon it'll be for the first time, and I'm not sure know what power usage to anticipate.

I try to use 12v or USB power as much as possible, and can only think of a couple of mains devices I use. The more demanding one is a breadmaker and, if I recollect, it only uses 550W peak and 550Wh total.

I can't say why, but I feel like a 1000W inverter won't be enough for future needs and would have guessed that liveabords might typically have a 2kW or 3kW one. I looked up power drills and some were 1200W, routers 1200W - 1500W.

It might normally make sense to buy a 1000W inverter now and just see if I need to upgrade in the future but, due to circumstances I can get a discount on a Victron right now, but only right now.

I'd love to hear what size of inverter you're using, what you run off it, and if you've ever felt constrained.

 

[RupertW]

Ours is 1kw most which of is only really used when fast charging the outboard.

Don’t want it any bigger at the moment as I don’t want batteries able to be drained too quickly

 

[Dockhead]

Just one data point --

We have a nominally 3000 watt one (Victron 24/70/3000 charger-inverter), but if you read the fine print it's really 2500 watts under ideal conditions, and if it's hot, 2000 watts.

It's more or less ok for our electric intensive boat (microwave, washer/dryer, electric kettle, etc. etc.) but it's certainly not oversized, and we have to be careful managing the loads when the inverter is on.

What kind of alternator do you have? If you have a heavy duty alternator, it's worth having a bigger inverter, because then you power normal AC power loads off the alternator when the engine is running -- incredibly useful. When motoring in calm weather, for example, wash and dry loads of clothes -- just barely manageable with this inverter, and 2.5kW school bus alternator. With a heavy duty alternator (which doesn't overheat when you take max power from it continuously) and suitable inverter, then you are virtually on shore power when the engine is running -- incredibly useful.

Another factor is battery power -- what size is your house bank? A large house bank, and most especially, if you have lithium batteries, is another factor which indicates a larger inverter, as you can then realistically power bigger loads off battery power.

My next boat (which I hope will be a new build) will have more inverter capacity than this, and a bigger alternator. Probably a gang of two Victron Multipluses like what I have now, which will add redundancy and which will give 4kW of reliable power, equal to a normal shore power connection. YMMV!

 

[lw395]

Ours is 500W continuous.
We don't need any serious 230V loads.
Kettle and fan heater are handy for winter marina stops, but not essential.
I believe bread was invented before electricity?
You make choices about your 'needs' in conjunction with the way you sail your boat.

 

[GHA]

I can't say why, but I feel like a 1000W inverter won't be enough for future needs and would have guessed that liveabords might typically have a 2kW or 3kW one.

In the market as well as a liveaboard, time to upgrade that cheapo 500W job from a decade ago

If you're looking a living mostly on the hook then a honda genny is well worth thinking about, for battery charging without running the engine and bigger power tools. I'm thinking a 1Kw true sine wave which should cover a kitchen little food processor which at the moment means digging out the genny so rarely gets used on the hook. Almost everything else is DC, buck or boost converters for the few little bits which need odd voltages.

 

[KompetentKrew]

Thanks for your reply, Dockhead.

I don't know the size of the alternator - wasn't top of my agenda when shopping for boats.

I couldn't see where to put even a small Daewoo washing machine, however much I want one.

For the sake of independence, if no other reason, I'd like a larger battery bank. But I'll have to see how it goes with this one initially, before spending the money.

It sounds a bit like your view is that there's no such thing as too much capacity - you'll find a way to use it. Is that fair?

 

[Graham376]

In the market as well as a liveaboard, time to upgrade that cheapo 500W job from a decade ago

If you're looking a living mostly on the hook then a honda genny is well worth thinking about, for battery charging without running the engine and bigger power tools. I'm thinking a 1Kw true sine wave which should cover a kitchen little food processor which at the moment means digging out the genny so rarely gets used on the hook. Almost everything else is DC, buck or boost converters for the few little bits which need odd voltages.

Our little processor works OK on 350w, for larger mixing wife works fine and uses little energy

 

[lw395]

Around here, when people talk about 'cake mixers' and suchlike, they're normally taking the mick out of electric outboards, or sometimes just anything under about 30HP.

 

[geem]

3kw low frequency inverter. Will run watermaker with engine running if generator fails. Also have a 500w inverter for charging 220v stuff like lecky toothbrushes

 

[Dockhead]

Thanks for your reply, Dockhead.

I don't know the size of the alternator - wasn't top of my agenda when shopping for boats.

I couldn't see where to put even a small Daewoo washing machine, however much I want one.

For the sake of independence, if no other reason, I'd like a larger battery bank. But I'll have to see how it goes with this one initially, before spending the money.

It sounds a bit like your view is that there's no such thing as too much capacity - you'll find a way to use it. Is that fair?

Well, to some extent, of course, more power is like more money -- always something to spend it on.

But really it all depends on what you're using it for.

On our last boat, we used very little AC power for anything, and were self-sufficient with solar power. It was fine. There's a dynamic relationship between having more power and needing more power. When it's not available, you find other ways to do stuff, or do without. When it is available, you find a lot of different ways to use it for greater comfort.

So it starts with how you want to use the boat.

My next boat will be more power intensive than this one -- no gas on board, so all electric cooking. Possibly even a dishwasher (uses far less water than washing by hand). Another aspect of the systems architecture of electrical power is that once you have enough power for one high power system, then you can add others at little cost -- it's synergistic.

And lithium makes it possible to capture power easily when it's abundant, and use it happily without worrying about finishing charges etc. like you do with lead-acid.

But it's also possible to be quite comfortable on boats with little AC power -- I think you have to look at the whole boat and how you plan to live on her.

 

[Pasarell]

I have a 350W inverter and rarely use it. I do also have a 2KW Honda suitcase generator and have only used it in anger once. Pretty much everything we use in the summer works from 12v sometimes needing a DC-DC converter. We spend the winter in a marina where shore power drives a microwave and kettle but they are unused in the summer

 

[TQA]

I have a 1200 watt and a 300w. The smaller one gets used for laptop razor VHF recharge etc.

One thing to watch out for when buying an inverter is that there is a difference in the output wave form, pure sine wave v modified sine wave.

Some devices with advanced electronics will fail when fed modified sine wave.

 

[duncan99210]

We’ve got a 1000 watt inverter which is over the top for just about everything we use it for; laptop (occasional), juicer 35 watts (frequent) and power tool batteries (occasional). Anything else with mains voltage demands is somewhere in the port aft cabin until we’re somewhere with shorepower.
I do take some delight in telling lady guests not to bother bringing their hairdryers and tongs with them as I can’t supply the electricity for them to be used.....